Back around 2003 when all of Chaos was together in one book my predominantly beastmen chaos army was looking for a boost from some heavy cavalry in the name of Chaos Knights. This was the test piece for just that. I wanted it to fit my beastmen theme, so I needed a knight that was more beastmen like. Why not an heavy armored centaur.
It merged the Chaos Knight/Empire Knight horse with a beastmen gor torso, chaos warrior weapon and shield.
And whole lot of other bits. The chest armor was all sculpted. The rivets along the bottom of the armor were added.
And I was going to mark the unit this would be apart as Khorne as you see on the shoulder.